Three-Dimensional Numerical Simulation of Flame Propagation in Spark Ignition Engines

1993 ◽  
Author(s):  
Xiaowei Zhao ◽  
Ronald D. Matthews ◽  
Janet L. Ellzey
Keyword(s):  
Numerical Simulation ◽  
Flame Propagation ◽  
Three Dimensional ◽  
Spark Ignition ◽  
Spark Ignition Engines

A phenomenological mixture homogenization model for spark-ignition direct-injection engines

2017 ◽  
Vol 19 (2) ◽  
pp. 168-178 ◽  
Author(s):  
Stefan Frommater ◽  
Jens Neumann ◽  
Christian Hasse
Keyword(s):  
Equivalence Ratio ◽  
Direct Injection ◽  
Three Dimensional ◽  
Control Unit ◽  
Spark Ignition ◽  
Engine Control Unit ◽  
Operating Conditions ◽  
Spark Ignition Engines ◽  
Ratio Distribution ◽  
Direct Injection Spark Ignition

In modern turbocharged direct-injection, spark-ignition engines, proper calibration of the engine control unit is essential to handle the increasing variability of actuators. The physically based simulation of engine processes such as mixture homogenization enables a model-based calibration of the engine control unit to identify an ideal set of actuator settings, for example, for efficient combustion with reduced exhaust emissions. In this work, a zero-dimensional phenomenological model for direct-injection, spark-ignition engines is presented that allows the equivalence ratio distribution function in the combustion chamber to be calculated and its development is tracked over time. The model considers the engine geometry, mixing time, charge motion and spray–charge interaction. Accompanying three-dimensional computational fluid dynamics, simulations are performed to obtain information on homogeneity at different operating conditions and to calibrate the model. The calibrated model matches the three-dimensional computational fluid dynamics reference both for the temporal homogeneity development and for the equivalence ratio distribution at the ignition time, respectively. When the model is validated outside the calibrated operating conditions, this shows satisfying results in terms of mixture homogeneity at the time of ignition. Additionally, only a slight modification of the calibration is shown to be required when transferring the model to a comparable engine. While the model is primarily aimed at target applications such as a direct-injection, spark-ignition soot emission model, its application to other issues, such as gaseous exhaust emissions, engine knock or cyclic fluctuations, is conceivable due to its general structure. The fast calculation enables mixture inhomogeneities to be estimated during driving cycle simulations.

Spark Advance Modeling of Hydrogen-Fueled Spark Ignition Engines Using Combustion Descriptors

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Saket Verma ◽  
L. M. Das
Keyword(s):  
Numerical Simulation ◽  
Alternative Fuels ◽  
System Development ◽  
Spark Ignition ◽  
Spark Ignition Engines ◽  
Ansys Fluent ◽  
Engine Design ◽  
Pressure Peak ◽  
Si Engines ◽  
Computational Fluid Dynamics Cfd

In-cylinder pressure-based combustion descriptors have been widely used for engine combustion control and spark advance scheduling. Although these combustion descriptors have been extensively studied for gasoline-fueled spark ignition (SI) engines, adequate literature is not available on use of alternative fuels in SI engines. In an attempt to partially address this gap, present work focuses on spark advance modeling of hydrogen-fueled SI engines based on combustion descriptors. In this study, two such combustion descriptors, namely, position of the pressure peak (PPP) and 50% mass fraction burned (MFB) have been used to evaluate the efficiency of the combustion. With a view to achieve this objective, numerical simulation of engine processes was carried out in computational fluid dynamics (CFD) software ANSYS fluent and simulation data were subsequently validated with the experimental results. In view of typical combustion characteristics of hydrogen fuel, spark advance plays a very crucial role in the system development. Based on these numerical simulation results, it was observed that the empirical rules used for combustion descriptors (PPP and 50% MFB) for the best spark advance in conventional gasoline fueled engines do not hold good for hydrogen engines. This work suggests revised empirical rules as: PPP is 8–9 deg after piston top dead center (ATDC) and position of 50% MFB is 0–1 deg ATDC for the maximum brake torque (MBT) conditions. This range may vary slightly with engine design but remains almost constant for a particular engine configuration. Furthermore, using these empirical rules, spark advance timings for the engine are presented for its working range.

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